The present invention relates to personnel tracking systems and methods generally, and more particularly to a gimbal mounted antenna system orientation maintaining system in remote units of a central control station monitored personnel tracking system, which remote units utilize satellite global positioning. In use, the present invention maintains an electromagnetic signal reception means of an antenna system therein in an essentially constant electromagnetic signal reception orientation with respect to at least one earth orbiting satellite, when the orientation of a structural frame xe2x80x9cbagxe2x80x9d element of a personnel tracking system remote unit, which contains the gimbal mounted antenna system, is changed.
It is well known that the orientation of an antenna system with respect to a transmission source of electromagnetic signals is critical to the capability of said antenna system to provide high quality reception of electromagnetic signals transmitted by said transmission source. For instance, a terrestrial based antenna system must have electromagnetic signal reception elements thereof oriented properly to receive electromagnetic signal transmission from an earth orbiting satellite. A non-limiting example of a system wherein orientation of electromagnetic signal reception elements of an antenna system with respect to an earth orbiting satellite is important to the operation thereof, is described in U.S. Pat. Nos. 5,072,396 and 6,100,806, which are incorporated by reference into this Disclosure as are applications Ser. Nos. 09/312,708, and 60/087,727. Said incorporated Patents describe statically mounted electromagnetic signal receiving antenna systems and the applications introduce gimbal mounting thereof.
Additional known Patents which are relevant to personnel tracking systems include a Patent to Kotoh, U.S. Pat. No. 4,673,936. Said 936 Patent describes a rescue transmitter apparatus which is adapted to be worn on a person""s wrist. Said transmitter apparatus sends a microwave signal which, in use, is received by a search and rescue craft thereby allowing relative, but not absolute, positioning of the transmitter apparatus, by use of a directional antenna. A Patent to Damell et al., U.S. Pat. No. 5,043,736 describes a hand-held apparatus which contains a Global Positioning System (GPS), which allows determining an absolute, (ie. longitude and lattitude), and a cellular telephone transmitter.
Several Patents have been proposed in the field of prisoner monitoring in house arrest scenarios. One is described in a Patent to Pauley et al., U.S. Pat. No. 4,885,571, wherein a xe2x80x9ctagxe2x80x9d device, which is worn by a prisoner, periodically is caused to transmit to a field unit. Receipt of the signal at a field unit is an indication that the xe2x80x9ctagxe2x80x9d is within a transmission range, but no absolute, or even relative, positioning data is made available. Another Patent, U.S. Pat. No. 5,493,694, describes a central station system which is used to send interrogation signals to a fleet of vehicles requesting that selected vehicles respond, which central station system then waits and listens for a response. The central station can also receive signals indicating that a fleet vehicle requires assistance, then respond with a signal which provides location information to other fleet vehicles, certain of which, if within a predetermined distance to the vehicle which requires assistance, can respond. U.S. Pat. No. 5,528,248 to Steiner et al., describes a hand-held personal digital location apparatus which has a (GPS) antenna and receiver which serves to provide location information, however, no mention of application to continuous tracking and monitoring of an individual is mentioned. U.S. Pat. No. 5,541,845 to Klein describes methods for monitoring adherence of a vehicle to prescribed planned route and/or time schedule. The vehicle can utilize a (CPS), or other location determining system. Said 845 Patent provides that Non-adherence to a specified route or time schedule causes the vehicle to send a signal to a central station. U.S. Pat. No. 5,552,772 to Janky et al., describes a location determination system used to determine the present location of a firefighter at a fire site or the like. One embodiment provides that a firefighter carry a unit that receives a signal from a group of sources. A central station interrogates the one or more of said units, which each respond with location information. While the system can store information, the remote units do not have processors which can store location information data or upload or download information showing past locations. U.S. Pat. No. 5,568,119 to Schipper et al., discloses a method and apparatus which is applicable to use in house-arrest settings, and allows monitoring the current location of a remote unit, which can be checked at selected times. An arrestee wears a location determining device which can combine with a (GPS) type system or ground based system. Either the remote unit or central station can be used to process information and the central station compares said location with prescribed boundaries to determine if the arrestee is staying therewithin. If an expected location determining signal is not received, or a received signal indicates that an arrestee has strayed outside allowed boundaries, the central station notifies appropriate authorities. The remote unit can include tamper detection equipment, and optionally, the remote unit can transmit position information in encrypted form. The 119 invention provides for periodic modification of allowed time scheduled arrestee positioning. A Patent to Hoshen, U.S. Pat. No. 5,461,390 describes a locator device which can be useful in house arrest and stalker detection. The device utilizes a polling type apparatus wherein a polling message is sent from a central unit to remote units. There is no provision for xe2x80x9creal-timexe2x80x9d detection of violations, or of any capability to upload or download data. U.S. Pat. No. 5,416,695 to Stutman et al., describes a method and apparatus for alerting patients and medical personnel of emergency medical situations. A telephone network is utilized to transmit information from a patient, and a (GPS) remote telemetry device also collects information for transmission to a host computer. When patient parameters exceed set ranges, an alarm is sounded. A xe2x80x9cpanic-buttonxe2x80x9d is also provided which permits the patient to directly contact the host computer. A Patent to Baumann, No. U.S. Pat. No. 5,416,468 describes a plurality of individual remote units on persons, which transmit location data to a xe2x80x9cfield unitxe2x80x9d at periodic intervals. If information is not received within a predetermined time range, an alarm may be triggered. The remote units can include xe2x80x9cdetectorsxe2x80x9d which sense environmental conditions and transmit said data along with location data. The Baumann remote units can only transmit data and do not have the capability to determine if it is received by the field unit, and the remote units do not store tracked information.
U.S. Pat. Nos. 4,682,155 and 5,268,670 to Shirley and Brasch et al., which focus on monitoring the movements of medical patients, are also known and disclosed.
Patents particularly relevant to the present invention antenna orientation system in a personnel tracking system, and a method of use for maintaining an electromagnetic signal reception means of an antenna system therein in an essentially constant desired orientation with respect to an electromagnetic signal transmission source, when the orientation of a structural frame element of said personnel tracking system is changed were also identified. Perhaps the most relevant is a Patent to Friedrich et al., U.S. Pat. No. 5,410,325 which describes an antenna assembly which is free to rotate about at least one axis parallel to the axis of rotation of an elevationally moveable dump truck bed. Another Patent, U.S. Pat. No. 5,512,912 to Ross et al., particularly in FIG. 4 thereof, provides a two axis gimbaled mounting which allows an antenna to maintain a predetermined position despite the influence of externally applied accelerations, including effecting satellite orientation. A chamber holds a damping fluid which serves in damping oscillations. U.S. Pat. No. 1,569,325 to Leib, describes a radio direction finder comprising a frame-ship antenna and a spherically curved antenna which mounts to a support. The radio direction finder further comprises a counter-weight below the support such that the axis can swing laterally in all directions and assume a vertical position regardless of the inclination of the support. U.S. Pat. No. 5,670,967 to Sarjala describes a method and system for mechanical stabilization wherein a body is supported at its center of mass, whereby no acceleration in any direction causes a torque induced by the inertial force. The body maintains its position in relation to the earth gravity field, even if accelerations and various kenetic states are applied at the point of support. A Patent to Gordon et al., U.S. Pat. No. 5,489,911 describes an antenna for use in Marine VHF Systems which includes a gimbaled device. U.S. Pat. No. 5,111,212 to DeSatnick et al. describes a radar antenna mount in which the antenna is mounted with its center of gravity below the pivot axis. Viscous damping is also provided to prevent uncontrolled swinging of the antenna. U.S. Pat. 986,806 to D""Antonio describes a reflector for a wireless antenna that is mounted via a bearing socket and a ball journal, such that the reflector is on one side of the bearing socket and a ball journal via a stem, and a counter weight is present on the opposite side of said stem. U.S. Pat. No. 4,920,350 to McGuire et al is disclosed as it describes a casing, a stage and an antenna mounted on the stage. Additionally disclosed for general purposes is U.S. Pat. No. 5,943,027 to Thill et al.
As mentioned, recently Issued Patents to the same Inventor which are disclosed for relevant background are U.S. Pat. Nos. 6,072,396 and 6,100,806.
Even in view of the prior art, there remains need for a system for continuous electronic monitoring and tracking of individual(s) at remote unit location(s) from a central control station (CCS), where each said remote unit comprises a global positioning system (GPS) with an antenna affixed thereto via a gimbaled stage means, such that the changing of the orientation of a remote unit antenna system electromagnetic signal reception means in use, does not cause said antenna system electromagnetic signal reception means to become oriented so that it does not receive position determining signal(s) from one or more earth orbiting satellites.
The present invention is a system for continuous electronic monitoring and tracking of monitored individual(s) from a central control station (CCS), and can be described as comprising one or more remote unit(s) (RU), each of which remote unit(s) (RU) contain geographic position determining means for determining the position thereof at determined time(s). Each remote unit (RU) has therein a programmable central processing unit (CPU) with accompanying memory storage which is connected to the position determining means, said combination having the capability to store determined position signals in combination with a generated time stamp. Said system for continuous electronic monitoring and tracking of monitored individual remote unit(s) each further comprise communication means connected to the programmable central processing unit (CPU) which enable transmitting data from the remote unit (RU) to the central control station (CCS). Said communication means further enable receiving data from the central control station (CCS) and providing said data to the central processing unit (CPU). The central processing unit (CPU) is programmed to accumulate time stamped remote unit (RU) position signal data at determined time intervals and transmit said accumulated position signal and time stamped data to the central control station (CCS) via a downlink. It is a critical element of the present invention system for continuous electronic monitoring and tracking of monitored individuals, that while communication means for receiving data from a present invention remote unit (RU) can be land based or utilize satellite links etc., the position determining means are of the type which receive electromagnetic radiation from at least one earth orbiting satellite, (ie. that is the position determining means constitute a global positioning system (GPS)).
It is further disclosed that a present invention system for continuous electronic monitoring and tracking of monitored individuals remote unit (RU) comprises an element worn on the body, (eg. typically on the wrist or ankle), of a monitored individual who""s position is to be tracked. Said element which is worn on the body on a monitored individual, in use, communicates with a nearby positioned xe2x80x9cbagxe2x80x9d. It is the nearby positioned xe2x80x9cbagxe2x80x9d that contains the majority of the just described remote unit (RU) elements, (eg. (CPU), memory etc.), including the (GPS) antenna system which is mounted thereto via the present invention gimbaled stage. It is to be understood that while cable has been demonstrated as a particularly functional means, said communication between said body worn element and said xe2x80x9cbagxe2x80x9d can be via any functional means, (eg. cable, fiber optics, ultrasound or electromagnetic transmission through a space etc.).
The present invention is specifically found in the combination of:
a remote unit of a system for continuous electronic monitoring and tracking of monitored individuals, which, as described, contains a global positioning system (GPA) antenna system which comprises electromagnetic signal receiving means; and
a gimbal mounted, (ie. gimbaled), antenna system mounting means, (eg. stage), which serves to mount said antenna system to a present invention remote unit xe2x80x9cbagxe2x80x9d structural frame element such that in use said gimbaled stage operates to maintain said electromagnetic signal receiving means oriented so as to receive electromagnetic signals from at least one earth orbiting satellite, when the xe2x80x9cBagxe2x80x9d structural frame is caused to change orientation.
It is to be understood that the preferred present invention gimbaled stage is affixed to an upper end of an elongated arm which has a counter-weight affixed to a lower end thereof, and said elongated arm is pivotally mounted to a present invention xe2x80x9cbagxe2x80x9d structural frame element, at a point between said gimbaled stage and counter-weight. Functionally, the benefit of the present invention is found in the fact that said present invention xe2x80x9cbagxe2x80x9d structural frame element can be rotated in an effective pendulum plane of said present invention elongated arm, without affecting an essentially constant orientation of said present invention antenna system electromagnetic signal reception means present on said invention gimbaled stage, with respect to an electromagnetic signal transmission means, (eg. an orbiting satellite).
The present invention then enables, via the gimbaled antenna system mounting, the maintaining of the orientation of a (GPS) antenna system electromagnetic signal receiving means essentially constant, and appropriate to receive electromagnetic signals from at least one satellite orbiting the earth, even when a xe2x80x9cbagxe2x80x9d containing said (GPS) antenna system is caused to be tipped so as to be positioned in various positions. Such xe2x80x9ctippingxe2x80x9d can occur where, for instance, a xe2x80x9cbagxe2x80x9d is knocked-over onto its side.
Continuing, a method of keeping electromagnetic signal receiving means of an antenna system oriented so as to receive signals from a source of electromagnetic signals, as applied to a system for continuous electronic monitoring and tracking of monitored individuals, comprises the steps of:
a. providing an antenna system in a system for continuous electronic monitoring and tracking of monitored individuals comprising electromagnetic signal receiving means affixed to a gimbaled stage, said gimbaled stage being affixed to an upper end of an elongated arm which has a counter-weight affixed to a lower end thereof, said elongated arm being pivotally mounted to a xe2x80x9cbagxe2x80x9d structural frame element, such that said xe2x80x9cbagxe2x80x9d structural frame element can be rotated in an effective pendulum plane of said elongated arm without affecting an essentially constant orientation of said antenna system electromagnetic signal reception means;
b. orienting said antenna system electromagnetic signal receiving means appropriately to receive electromagnetic signals from said source of electromagnetic signals;
c. causing said xe2x80x9cbagxe2x80x9d structural frame element to rotate in an effective pendulum plane of said elongated arm;
such that said counter-weight affixed to the lower end of said elongated arm is continuously attracted by gravity toward the earth with the result that, via rotation of said elongated arm about said pivotal mounting to said xe2x80x9cbagxe2x80x9d structural frame element with respect to said xe2x80x9cbagxe2x80x9d structural frame element, the orientation of said antenna system electromagnetic signal receiving means present on the said gimbaled stage remains essentially constant while said xe2x80x9cbagxe2x80x9d structural frame element is caused to be so rotated.
It is specifically disclosed that an effective xe2x80x9cpendulum planexe2x80x9d of said elongated arm can be essentially three-dimensional, and is not limited to a fixed two-dimensional plane as referenced to said xe2x80x9cbagxe2x80x9d structural frame element.
It is further noted that practice of the present invention method of maintaining the orientation of an antenna system electromagnetic signal receiving means appropriate to receive electromagnetic signals from an orbiting earth satellite, can involve practice with a variety of types of antenna systems. For instance, the present invention can be applied to continuously maintain an essentially flat patch antenna system electromagnetic signal reception surface means in a plane which is essentially orthogonal to the vector direction of the force of gravity. As well, the present invention can be applied to continuously maintain an elongated dimension projection direction of a whip or helical antenna system electromagnetic signal reception means oriented essentially parallel to the vector direction of the force of gravity or, alternatively stated, along a radius which projects from the center of the earth outward toward the position of an electromagnetic signal transmitting earth orbiting satellite, said radius intersecting the surface of an idealized spherical model of the earth at a ninety degree angle.
While a present invention xe2x80x9cbagxe2x80x9d has been described in prior co-pending parent patent applications by the inventor, (eg. Ser. Nos. 08/840,057 and 08/367,057), and while gimbaled stage mounting of antenna systems to structural frames are independently known, no known reference describes a system for continuous electronic monitoring and tracking of monitored individuals comprising a global positioning system (GPS) electromagnetic signal receiving means affixed to a gimbaled stage, and method of use, as described herein. Said combination provides particular benefit in situations wherein a present invention xe2x80x9cbagxe2x80x9d is prone to being knocked-over in use.
The present invention will be better understood by reference to the Detailed Description Section of this Disclosure, in combination with the Drawings.
It is therefore a primary purpose of the present invention to provide a gimbal mounted antenna system in remote unit(s) of a system for continuous electronic monitoring and tracking of monitored individual(s) from a central control station.